1. Field of the Invention
The present invention relates to automatic door operators and more particularly to a door opener and closer.
Automatic operators for entry and exit doors are in general use, such as for airports, department stores, office buildings and other high volume traffic areas where pedestrians may be carrying luggage, or the like. Automatic operators for such doors are usually installed in the transom area of the door and are generally actuated by walk-on approach mats or an electric eye. Automatic door operators are generally relatively complex and, therefore, initially expensive as well as costly to maintain since they require frequent service and experienced service personnel.
2. Description of the Prior Art
Automatic door operators presently in use, whether they be of the type which opens the door and utilize a conventional door check or wound up spring for closing the door or are of the type which both opens and closes the door, have generally been powered by an electric motor having its drive shaft horizontally disposed. This horizontal disposition of the drive shaft is necessitated for convenience in a space restricted area for connection with the necessary worm screw and gear train drive interposed between the motor drive and door connected operating arm, the gear train usually being in an oil filled gear case to maintain the gears lubricated which is the most frequent source of maintenance problems.
U.S. Pat. No. 3,874,117 is an example of this type of electric motor drive gear train door opener.
This invention is distinctive over the prior art and this patent by disposing a door opening and closing drive motor with its drive shaft vertical and connecting the motor with a door operating arm through a transom drive formed by a series of cog belts and pulleys which also includes a friction clutch as a safety feature and for the protection of the equipment and increasing its useful life.